Methods and apparatus for suspension lock out and signal generation

ABSTRACT

Methods and apparatus for regulating the function of a suspension system are disclosed herein. Suspension characteristics often contribute to the efficiency of a suspended system. Depending on the desired operating parameters of the suspended system, it may be desirable to alter the functional characteristics of the suspension from time to time in order to maintain or increase efficiency. The suspension hereof may be selectively locked into a substantially rigid configuration, and the damping fluid may be phase separated and/or cooled to increase damping rate during use (or offset rate degradation). The suspension hereof may generate power usable to achieve any or all of the foregoing or to be stored for use elsewhere in the suspended system or beyond.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of and claims the benefitof co-pending U.S. patent application Ser. No. 14/562,002 filed on Dec.5, 2014 entitled “METHODS AND APPARATUS FOR SUSPENSION LOCK OUT ANDSIGNAL GENERATION” by David M. Haugen, and assigned to the assignee ofthe present application, which is incorporated herein, in its entirety,by reference.

The U.S. patent application Ser. No. 14/562,002 is a continuationapplication of and claims the benefit of U.S. patent application Ser.No. 14/180,206 filed on Feb. 13, 2014 and is now U.S. Pat. No.8,925,933, entitled “METHODS AND APPARATUS FOR SUSPENSION LOCK OUT ANDSIGNAL GENERATION” by David M. Haugen, and assigned to the assignee ofthe present application, which is incorporated herein, in its entirety,by reference.

This U.S. Pat. No. 8,925,933 is a continuation application of and claimsthe benefit of U.S. patent application Ser. No. 13/761,555 filed on Feb.7, 2013 and is now issued U.S. Pat. No. 8,684,367, entitled “METHODS ANDAPPARATUS FOR SUSPENSION LOCK OUT AND SIGNAL GENERATION” by David M.Haugen, and assigned to the assignee of the present application, whichis incorporated herein, in its entirety, by reference.

The U.S. Pat. No. 8,684,367 is a continuation application of and claimsthe benefit of U.S. patent application Ser. No. 12/547,381 filed on Aug.25, 2009 and is now issued U.S. Pat. No. 8,393,446, entitled “METHODSAND APPARATUS FOR SUSPENSION LOCK OUT AND SIGNAL GENERATION” by David M.Haugen, and assigned to the assignee of the present application which isincorporated herein, in its entirety, by reference.

The U.S. Pat. No. 8,393,446 claims priority to and benefit of U.S.Provisional Patent Application 61/091,640 filed on Aug. 25, 2008entitled “MECHANICAL SUSPENSION LOCK OUT” by David M. Haugen, which isincorporated herein, in its entirety, by reference.

FIELD OF THE INVENTION

Embodiments of the invention generally relate to methods and apparatusfor selectively operating a suspension component. Some embodimentsrelate to generating a signal and/or current while operating asuspension component.

BACKGROUND OF THE INVENTION

Suspension systems and more particularly vehicle and bicycle suspensionsystems have been available for many years. The predominant form ofvehicle suspension, and more specifically, bicycle suspension dampers,are telescopic. Suspension systems typically comprise a spring forenergy storage and a damping mechanism for energy dissipation.Suspension systems are used to absorb impact and/or vibration in a widevariety of configurations including vehicle seats, vehicle wheels,industrial machinery, watercraft hull/cabin or cockpit interface,bicycle seat posts and many others. Vehicle wheel suspension oftenincludes a damping mechanism for dissipating energy (from wheel movementcaused by disparities in the terrain over which the vehicle travels) anda spring mechanism for storing energy for rebound. Damping assembliesoften convert wheel movement into heat by means of fluid friction in afluid filled dashpot (piston and cylinder) type damping device. Springmechanisms may take many forms including, coiled springs, elastomerbumpers, compressible fluid (e.g. gas, silicone oil), suitablecombinations thereof or other suitable energy storage mechanisms. Twowheeled vehicle front forks and rear shocks are designed such that adampening piston is slidably contained within a cylinder. The cylindertypically contains a damping fluid (e.g. liquid oil) or fluids and thepiston typically includes a valve or orifice through which the fluidflows from one side of the piston to the other as the piston movesaxially within the cylinder. In typical bicycle suspension forks thereare two cylinders and two pistons with one each paired telescopically oneither side of a front wheel. Bicycle suspension forks are described inU.S. Pat. Nos. 6,217,049 and 5,186,481, each of which patents isincorporated herein, in its entirety, by reference. A bicycle rear shockunit is described in U.S. Pat. No. 7,147,207 which is incorporatedherein, in its entirety, by reference.

When a bicycle is equipped with front or rear suspension or both, itwill tend to “bounce” in response to the cyclical force exerted on thepedals. There a couple of reasons for that but the result of any bounceis power loss. Suspension “squat” power loss on motorized vehicles maynot be significant because the horsepower available is often more thanadequate to compensate for the loss while still providing ample usablepower. That may not be true of human powered vehicles such as bicycles.A typical adult human in good physical condition can supplyapproximately one half horsepower to the peddle crank of a bicycle. Anelite athlete may supply horsepower approaching 0.6. In any case thatisn't much horsepower and any loss is usually noticeable.

Another power loss mechanism involved is that of “chain power squat.”When, for example, a chain exerts a forward directed pulling force onthe rear sprocket of the bicycle, that force vector will tend toupwardly rotate a rear suspension swing arm about its pivot point at theframe connection if the chain, as it runs between the drive (chain ring)and driven (rear) sprockets, extends above the pivot point. Most oftenthe chain does run above the pivot point and as force is exerted on thechain some of the force is expended in compressing the rear suspension(as the swing arm rotates due to the chain moment).

Another power loss mechanism is the force induced bounce that directlyresults from the rider's interaction with the pedals. A bicycle ridercan usually exert more force downwardly on a pedal than upwardly. Thatmeans that the maximum force exerted on the bicycle power crank movesalternately from side to side of the bicycle laterally, as each pedal ispushed through a down stroke. The asymmetric and cyclical nature of thepeddling action induces some bounce in both front and rear suspensionunits on a bicycle. As previously discussed, compression of suspensionrequires power. That power comes from one source on a bicycle and thatis the rider.

In order that a bicycle rider may maximize the power delivered todriving the bicycle forward and minimize suspension compression waste(due to pedal “bob” and/or “squat”), there is a need for suspensionunits that can act as rigid units when suspension characteristics arenot required, yet act to provide shock absorbsion when needed.

As previously mentioned, vehicle suspension systems are often damped bymeans of a piston traversing a liquid (e.g. hydraulic oil) filledcylinder arrangement. In such arrangement the piston is forced,alternatingly by terrain induced compressive loads and spring inducedextension loads, through the liquid filled cylinder in response tooperation of the suspension. Impact energy imparted to the suspension byterrain variation is dissipated by the damping system in the form ofheat. Heat, generated by friction between the damping fluid and thetraversing piston, builds up in the damping fluid and surroundings asthe suspension is cycled. When the suspension is used vigorously, theheat build up can exceed the natural rate of heat transfer from thesuspension to the surrounding atmosphere. Such heat build up canadversely affect the operation of the suspension damper. For example,the heat build up in the damping liquid will correspondingly change(e.g. lower) its viscosity and/or shear strength. Such changes canaffect the damping force generated (and energy dissipation) by thedamping piston during operation and may render the damping mechanismineffective.

Accordingly there is a need for a selectively rigid suspension unit.Further, there is a need for a suspension unit that can be placed in arigid condition without relying on hydraulic or other fluid lock out.There is a need for a vehicle suspension having increased heatdissipation characteristics. Further there is a need for a vehiclesuspension unit that can convert vehicle movement to electric power.Further there is a need for a vehicle suspension unit that can use powergenerated therein to increase performance of the suspension.

SUMMARY OF THE INVENTION

Some embodiments of the present invention include methods and apparatusfor mechanically fixing one part of a suspension mechanism to anotherpart of the suspension mechanism such that the parts are substantiallyunmovable in relation to each other. Some embodiments include methodsand apparatus for converting induced suspension movement into usableand/or storable energy such as electric current/voltage. Someembodiments include methods and apparatus for transferring heat from asuspension and further include methods and apparatus for generatingpower required to operate heat transfer enhancement mechanisms. Someembodiments include methods and apparatus for automatically regulatingpower generation and/or heat transfer enhancement. Some embodimentsinclude methods and apparatus for adjusting damping fluid flow rates tochange damping rates in proportion to changes in suspension temperature.Some embodiments include dynamically adjustable dampening fluids foraltering damping rates in proportion to external input. Some embodimentsinclude methods and apparatus for separating gas and liquid phases ofdamping fluid to tend to return damping fluid to a pre-use state.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features can be understoodin detail, a more particular description, briefly summarized above, maybe had by reference to embodiments, some of which are illustrated in theappended drawings. It is to be noted, however, that the appendeddrawings illustrate only certain embodiments and are therefore not to beconsidered limiting, for the invention may admit to other equallyeffective embodiments.

FIG. 1 shows a telescopic bicycle fork.

FIG. 2 shows a suspension locking mechanism.

FIG. 3 shows a suspension locking mechanism.

FIG. 4 shows a suspension damper including a linear generator and acooling circuit.

FIG. 5A shows a bicycle shock absorber according to one embodiment.

FIG. 5B shows a detailed portion of the shock absorber of FIG. 5A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

One embodiment hereof will be described as applied to a bicycle fork. Itwill be appreciated that such embodiments are equally applicable to rearsuspension units or other suspension units that include relativelymovable parts that may be selectively immobilized in relation to oneanother.

Referring to FIG. 1 of U.S. Pat. No. 6,217,049; shown is a front forkassembly. A modified copy of the FIG. 1 is included as FIG. 1 herein andhas been marked with a view A-A. Inner tube 16 is shown telescopicallyextending within outer tube 18 wherein the tubes 16, 18 have asubstantially common longitudinal axis.

FIG. 2 shows an embodiment of a mechanical suspension lock schematicallydepicted within portion A-A as specified in FIG. 1 including tubes 16,18and wiper (not numbered). FIG. 2 shows an embodiment of a system forimmobilizing tube 16 relative to tube 18 thereby allowing for selectivecreation of a rigid fork comprising tubes 16 and 18. The incidence ofother dampening components inside the fork tube or tubes is of noconsequence regarding the shown embodiment. FIG. 2 shows a modifiedouter tube 18. The tube 18 includes an annular recess 4 and asubstantially incompressible elastic element 1 is contained within therecess 4. The elastic element 1 may comprise any suitable material suchas, for example, elastomer, rubber, or thermoplastic. In one embodimenta feature of the elastic element 1 is that due to its substantialincompressibility, and bulk modulus, a first force exerted in onedirection one the element will cause corresponding deformation of theelement 1, and force exertion by the element 1, in a directionsubstantially orthogonal to the first force. In lay terms the element 1may be exemplified as a rubber donut. When compressed axially andconstrained radially by the outer surface (inside tube 18) of the recess4, the compressed donut will bulge inwardly (and exert pressureoutwardly against the constraint) until it contacts and becomesconstrained by the outer surface of the inner tube 16. Once the element1 contacts the inner tube 16 it will exert a force (pressure over thearea corresponding to the length of contact) on the outer surface oftube 16 proportional in magnitude to the axial compression force exertedon element 1. Such a force can be quite high, particularly if the axialcontact length and circumference (area) are significantly great (note:the force can be adjusted by design and one factor is the chosen contactarea). The frictional constraint between the element 1 and the tube 16will be a function of the normal force (or force per unit area) betweenthe parts and the coefficient of friction. By application of asufficient axial force on element 1, which is contained within and fixedrelative to tube 18, the inner tube 16 and the outer tube 18 can berelatively immobilized thereby resulting in a simple and rigidly lockedout suspension system. Principles of expanding elastomer elements aredescribed in U.S. Pat. No. 5,813,456 which is incorporated, in itsentirety, herein by reference. Note that the principles describedtherein are in reference to a rubber element that expands radiallyoutward in response to an applied axial force.

In the embodiment of FIG. 2, axial force is applied to the element 1 bya threaded element compression nut 2. A rider may optionally turn thecompression nut, for example clockwise, so that right hand inter-engagedthreads (compression nut male thread 6 and recess 4 female thread 5)cause the compression nut 2 to move axially deeper into recess 4 therebycompressing element 1 and bulging element 1 into contact with an outersurface of tube 16. The effect of that movement is shown in the “beforeand after” respectively left and right of centerline views in FIG. 2.Note that the nut 2 is advanced downwardly in the right side view.

In one embodiment axial force is applied to element 1 by means of acable operated annular ball cam mechanism. In one embodiment nut 2 isreplaced by a rotational cam and element 4 is capped by a solid washer(e.g. metallic). Cam balls are interposed between the cam and the washerand the balls are recessed into semi-spherical cavities in the washer(such that they remain in fixed location relative to the washer). Theballs are engaged by rotational cam surfaces on the cam nut 2′. A cableis configured to be manually operable from a cockpit of the vehicle andin operation to pull the rotational cam 2′ to rotate about the axis oftubes 16, 18. Such rotation causes the cam to force downwardly on theballs thereby exerting an axial force on the washer and correspondinglyon element 1. Cylindrical ball cam mechanisms are described in U.S. Pat.Nos. 6,199,669 and 6,520,297, each of which is incorporated herein, inits entirety, by reference.

FIG. 3. shows a slightly modified detail section B-B of FIG. 2. Themodification of FIG. 3 over FIG. 2 relates to an optional embodiment forthe element 1 of FIG. 2 and that element is designated element 3 in FIG.3. The recess 4 of FIG. 3 has a modified lower surface 9 where thatsurface is inclined at some angle 8 relative to a plane perpendicular tothe longitudinal axis of the tubes 16,18. The element 3 is optionally asolid ‘C’ shaped ring or segmented ring having an angle corresponding toangle 8 beveled on a lower surface thereof. When element 3 is movedaxially downward, by for example compression nut 2 as previouslydescribed, the angle on element 3 interacts with the angle 8 therebyurging element 3 radially inward into contact with an outer surface oftube 16. The amount of radial inward force is a function of the forceexerted on element 3 by nut 2 and the tangent of angle 8. Theaxial/radial force relationship may be adjusted using those designvariables. It may be appreciated that element 3 may be urged into adiametrical recess (not shown) in a surface of tube 16. It may also beappreciated that any of the components shown to be directed radiallyinward may be directed radially outward and vice versa. In other wordsthe element 1,3 may be on an exterior recess of an inner tube and theaxial force may urge the element radially outward toward an innersurface of an outer tube. Principles of segmented gripping rings or“slips” are described in U.S. Pat. No. 5,813,456 which is incorporatedherein, in its entirety, by reference.

While the gripping and immobilizing system embodiments shown hereindepict a particular location on a suspension unit it will be appreciatedthat such components, in the same, or alternative embodiments may bepositioned at almost any location inside a suspension dampening fluidchamber or external of such chamber (external example shown) andelsewhere on the suspension so long as two relatively moving componentsof the suspension are accessible by design for integration of a grippingsystem. It is appreciated that the suspension to be mechanically lockedmay be any suitable suspension (e.g. that suspending wheels, seats,integral to seat posts, machinery). It is appreciated that relativelymoving parts may be affixed to moving suspension parts for the specificpurpose of using such affixed parts for immobilization. It may beappreciated that an elastic element 1 may allow for some vibrationdamping between tubes 16,18 thereby providing a more comfortable bicycleride while minimizing pedal bounce.

The U.S. Pat. Nos. 5,186,481, 7,147,207 and 6,217,049, as well asothers, describe suspension units in which bounce is minimized (noteliminated) with the use of hydraulic “lock out” valves. Such valves,regardless of specific fork designs or configurations, all operate toclose or throttle the damping fluid flow path whereby fluid wouldnormally flow out of a compression side chamber formed by a dampeningpiston. When the suspension is “locked out” the bounce is the suspensionis typically limited by the compressibility of damping fluid “locked in”the compression chamber of the suspension unit. Unfortunately, bounceremains in the system and is the volume of the “locked” compressionchamber is large such bounce (system compressibility) can besignificant.

Hydraulic lock out suspension systems are equipped with a pressurerelief valve that bypasses (or otherwise relives) the lock out valvewhen pressure in the compression chamber reaches a certain value. Thatpressure relief valve or “blow off valve” is necessary in case a largeforce is imparted to the suspension while “locked out.” As force isimparted to the locked out suspension pressure in the compressionchamber is increased. A large enough force may generate a fluid pressurehigh enough to damage components of the suspension (e.g. burst thecompression chamber). Because the magnitude of possible forces isdifficult to limit, a blow off valve is added to relieve over-pressurecorresponding to such a force. Blow off valves and related “compressionchambers” are described in U.S. Pat. No. 7,163,222 and US PatentApplication Publication No 2007/0007743, each of which is incorporatedherein, in its entirety, by reference.

Because the lock out system and blow off valves of hydraulic lock outsystems are fluidic in nature they are subject to malfunction ifcontaminated by for example particulate matter. Furthermore, theperformance of such systems depends on fluid properties such asviscosity and shear strength and those properties are subject to changewith time and with temperature.

Because the lock out system is hydraulic, complexity is added to thesuspension. Additional components include a lock out valve andassociated adjustment controls, a blow off valve and associatedadjustment controls and other associated hydraulic system controlmechanism feed through and seals.

While the suspension lock out system described herein may be used tolimit vehicle movement by “locking” the suspension, one embodimentaccommodates issues that are relevant when the suspension is active(i.e. when the lock out is not engaged). Because a vehicle suspensionsystem 100 is, when in use, constantly subjected to alternating forcesand is compressed and extended cyclically in response to those forces,such vehicle suspension may, in one embodiment, be configured for use asa bi-directionally acting linear motor. In one embodiment, one of thedamping piston rod (shaft) 105 and the damping cylinder 110, or portionthereof or attached thereto (structure through which the piston rodmoves axially), is configured to include a wire motor winding 115 andthe other of the cylinder 110 or piston rod 105 configured to includeone or more permanent magnets 120. The relative and cyclic axialmovement between the rod and the cylinder (i.e. the magnet and thewinding) produces an electric current within the winding. FIG. 4 shows asuspension 100 including a winding 115 within a wall of a dampingcylinder 110 and a permanent magnet 120 within a piston rod 105. Thewinding power output terminals 125 extend through an out housing of thesuspension 100 and are available to conduct generated electric power toits point of use. U.S. Pat. Nos. 6,952,060; 3,842,753; 4,815,575;3,941,402; 4,500,827; 5,578,877; 5,347,186; 5,818,132; 3,559,027;3,861,487; 3,921,746; 3,981,204; 5,036,934; 7,569,952; 4,032,829; and4,387,781, each of which is incorporated, in its entirety, herein byreference, describe various linear generator (e.g. linear motor based)configurations for using reciprocal motion to generate electrical power.

In one embodiment, a cooling circuit 130, such as a thermo-electricgenerator (e.g. “TEG” described in greater detail herein), is attachedto a wall 110 of the damping cylinder to facilitate heat transferbetween the cooling circuit 130 and the wall 110. Electric power isconducted, via conductors 140, from the winding terminals 125 to theinput terminals of a power conditioner 135. The power conditioner 135may be any suitable power conditioner, such as for example an AC/DCconverter, a DC/DC converter, a transformer, a battery, a capacitor orany suitable combination thereof or other suitable conditioner as may berequired to power the cooling circuit 130. Conditioned power isconducted, via conductors 140, from the output terminals of the powerconditioner 135 to the input terminals 145 (typical) of the coolingcircuit 130. As the piston rod 105 moves back and forth axially indirection 150, the magnet 120 moves relative to the winding 115. Thatcyclic movement generates and electric current within the winding 115which as described powers the cooling circuit which in turn conductsheat away from the damper 100.

As an alternative or additional option, piezo electric crystals may beattached to a portion of the piston that is subjected to axial fluidpressure induced forces during operation of the suspension. In oneembodiment an area along the piston “skirt” or near the edge whereproximity to the walls of the cylinder through which the piston moves,creates a high fluid shear force in the fluid layer between the cylinderand the piston. Such shear stress in the fluid (i.e. viscous drag)operates to deform the piezoelectric crystal thereby generating acurrent. The piezoelectric structure is deformed cyclically at eachreversal of piston direction (cyclic stroke of the suspension) and inresponse to such deformation the piezo generates a electric current. Inone embodiment the piezoelectric structures may be placed on a face orfaces (front/back, top/bottom, compression/rebound) of the piston anddeformation of the piezo structure(s) is induced by dynamic fluidpressure buildup due to damping force generation. In one embodimentpiezoelectric devices are places proximate the ends of the dampingcylinder and dynamic fluid pressure generated by damping action acts onthose devices during compression and/or rebound pressure buildup. In oneembodiment, piezoelectric structures are placed within a damping pistonsuch that fluid flow generates dynamic vibration of the piezoelectricstructures and thereby generates electric power. It is noteworthy thatwhile a damping piston and cylinder are used herein to exemplifyembodiments of an electric current and/or voltage generating shockabsorber, the principles disclosed herein are equally applicable to agas spring piston and cylinder combination of a suspension. Further, thepiezoelectric devices may be places at an end or ends of a compressionspring of a vehicle suspension thereby generating current duringdeformation of the piezoelectric structure under cyclic spring loadingand corresponding axial force on the piezoelectric structure. Optionallya mechanical spring such as a coiled spring may comprise and electricwinding or permanent magnet of the linear motor described herein. Aplurality of piezoelectric devices may be placed on the piston facesand/or the piston skirt or any suitable combination thereof. A vehiclesuspension may be equipped with a combination n of piezoelectricgenerators and linear motor structures. For purposes hereof, discussionsof electric motors and generators are substantially interchangeable. Inprinciple an electric motor generates movement when a current is appliedthereto. Conversely the same structure will generate electric currentwhen movement is applied thereto. Such is particularly applicable topiezoelectric structures and therefore examples of piezo motors includedherein are suitable as examples of electric generators and vice versa.U.S. Pat. Nos. 5,806,159; 5,872,418; and 7,208,845, each of whichpatents is incorporated, in its entirety, herein by reference, describepiezoelectric generators and motors that are suitable for use inembodiments hereof. FIG. 4 shows a piezoelectric generator 155 (e.g. ofthe flow operated type described in U.S. Pat. No. 7,208,845) fixedwithin a fluid flow path 160 through piston 165. As the piston 165reciprocates, during operation of the damper 100, fluid flowing 160causes piezo generator 155 to vibrate (e.g. at resonance) therebygenerating electric output. Such electric output is conducted, viaconductors (not shown) through piston rod 105 and such conductor outputterminals may be located at an end (not shown) of piston rod 105. Anysuitable combination of the foregoing may be used.

Thermo-Electric generators or “TEG”s are special circuits that EITHERremove heat from one surface (the “cold” surface) of the circuit toanother surface (the “hot” surface) upon application of an electriccurrent to the circuit OR generate a current upon application of atemperature differential across the opposing “hot” and “cold” surfacesof the circuit. In one embodiment, TEGs may be based on the PeltierEffect and correspondingly constructed from thin ceramic wafers havingalternate P and N doped bismuth telluride sandwiched between them. SuchTEGs may be simply constructed using thermoelectric materials such aslead telluride, germanium telluride and cesium telluride. Otherthermoelectric effects (and mechanisms usable in accordance herewith)include the Seebeck Effect and the Thomson Effect. U.S. Pat. Nos.6,141,969; 7,523,617; 5,040,381; and 5,687,575, each of which isincorporated, in its entirety, herein by reference, describe theprinciples of thermo-electric circuit operation and application.

In one embodiment, as shown in FIG. 4, a damping piston shaft (or rod)105 and a corresponding damping cylinder 110 are equipped, as disclosedherein or otherwise, to generate electric current (or voltage if opencircuit) in response to relative movement there between. At least aportion of the housing of the damping system is equipped with at leastone TEG(s) 130 such that the “hot” surface of the TEG is in primarythermal communication with the ambient surroundings of the dampingsystem (or a secondary cooler, or a heat sink, or a combustion engineintake manifold or any environment suitable for heat use or disposal)and the “cold” surface of the TEG 130 is in primary thermalcommunication with the damping structure (e.g. damping fluid) 110. Suchthermal communication may be facilitated by direct contact or may be viaa suitable thermal conduit (not shown). A current is generated byoperation of the generator equipped suspension 100 and at least aportion of that current is connected to operate the TEG(s) 130.Optionally a heat sink (not shown) may be included and placed in thermalcommunication with the “hot” side of the TEG 130. Such a heat sink aidsin conducting heat away from the suspension 100 and may be equipped withheat dissipation mechanisms such as cooling fins. If the vehiclesuspended by such TEG equipped suspension 100 further includes a watercooling (or other powered cooling) system, the heat sink mayadvantageously be placed in thermal communication with such coolingsystem.

Typically, a suspension system comprising an electric generatingembodiment and TEG(s) as disclosed herein generates more electricitywhen subjected to extremely “bumpy” terrain versus relatively smoothterrain. Although the bumpy terrain will generate more heat in thesuspension (and correspondingly more heat build up potential), thehigher current flow, caused by more frequent cycling of the suspension,from the electric generating systems (as disclosed herein) will providemore power to the TEG(s) and will correspondingly result in a greater“heat split” (up to the limit of the TEG) between “hot” and “cold” TEGsurfaces. Such greater heat split will result in a higher cooling ratefor the suspension. In lay terms: the harder the auto-cooling suspensionhereof is worked, the more it will tend to cool itself off.

Optionally the suspension system can be “smart” such that the TEG(s)only activates when needed. In one embodiment a simple temperaturesensor (proximate the damping fluid and not shown) and microprocessor(e.g. the power conditioner 135 may include or comprise a programmableor preprogrammed microprocessor and power output switch or modulator)controlled switch turn the TEG on and off or modulate current flowthereto based on operating temperature of the suspension 100. In oneembodiment, there is an intermediate cylinder (not shown) mountedcoaxially between the piston shaft and the damping cylinder. Theintermediate cylinder, rather than (or optionally in addition to) thepiston shaft, includes either the magnet or the winding (and/orpiezoelectric structures) and the damping cylinder (or air springcylinder) there around includes the other of the winding or magnets. Insuch an embodiment, relative axial movement between the intermediate anddamping cylinders generates electric current (solely or in addition toother current generating mechanisms present in the suspension thereof).In one embodiment there is a layer of fluid (e.g. damping fluid) betweenthe intermediate cylinder and the damping cylinder. At lower (e.g.ambient or normal operating) temperatures, the viscosity and shearstrength of the damping fluid are such that the oscillation of thepiston shaft within the intermediate cylinder are insufficient to causesubstantial movement of the intermediate cylinder within the dampingcylinder (i.e. the fluid between the intermediate and damping cylindersis strong enough that the frictional forces therein maintain a dynamicaxial “fix” between the intermediate and damping cylinders). As such, atlow temperature no significant electrical current is generated inresponse to the configuration of the intermediate cylinder within thedamping cylinder because they are not relatively movable. When, however,the damping unit heats up in response to more vigorous use, the fluidlayer between the intermediate and damping cylinders becomes lessviscous (i.e. “thinner”) and the frictional force of the piston movingwithin the intermediate cylinder, in addition to providing damping,causes the intermediate cylinder to move axially relative to the dampingcylinder. The relative movement of the intermediate and dampingcylinders generates electric current which in turn may operate at leastone TEG(s) affixed to the damper. The intermediate and damping cylinderswill continue in relative axial movement until the system issufficiently cooled by the TEG(s) to allow the fluid between those twocylinders to “thicken” and thereby once again “lock” the cylinders fromrelative axial movement (until they become reheated due to lack ofcooling and the cycle begins again).

Optionally a suspension comprises TEG(s) placed suitably in relation toheat generating portions of the suspension and the TEG(s) generateelectric current in response to the heating of the suspension in use.The heat generated by the suspension actually powers the TEG, causing itto generate electric current. In FIG. 4 such a configuration wouldinclude the TEG 130 wherein the TEG terminals 145 would, in this TEGelectric generator embodiment, represent electric output terminals fromwhich usable electricity may be conducted to a suitable power use point(e.g. battery, valve, capacitor). When the TEG electric output leads areshunted or connected to a high current input battery (or capacitor)through a suitable current conditioner (e.g. DC/DC converter) thecurrent flow will facilitate the passive conduction of heat away fromthe suspension (to be used in generating current). The correspondinglygenerated current may be used to power “smart” systems associated withthe suspension and/or the vehicle generally. Note that any or all of theforegoing electricity generating systems may be used in any suitablecombination.

U.S. Pat. No. 7,374,028 (the “'028” patent), which is incorporated, inits entirety, herein by reference, describes a bicycle shock absorberhaving a “piggy back” gas charged damping reservoir. Optionally,electric current and/or voltage generated as disclosed herein may beused to control at least one valve opening(s) within the damping systemsuch that at lower fluid viscosities (e.g. higher temperatures), forexample, valves are closed or throttled. FIG. 5A shows a shock absorberof U.S. Pat. No. 7,374,028 subject to the present modification from thatpatent as shown in FIG. 5B and as further described herein. In oneembodiment valves control the flow of damping fluid (and hence thedamping rate) and when adjusted may compensate for varying viscosity ofthe damping fluid. Suspension may include a gas pressure charge orchamber in pressure communication with the damping fluid (e.g. oil) tocontrol or set static damping fluid pressure. As the suspension heats sothe gas charge may heat and thereby increase the static pressure of thedamping fluid disadvantageously. In one embodiment the cooling systemhereof operates to cool the gas charge thereby providing a stable staticdamping fluid pressure.

Referring to FIG. 5A herein (from the '028 patent), intensifier assembly510 is shown in conjunction with damper assembly 630. FIG. 5B shows anembodiment of an intensifier valve 511 for use with the principlesdisclosed herein. In one embodiment the intensifier valve 511 of FIG. 5Breplaces the assembly 510, as shown in FIGS. 15, 17 of the '028 patentand elsewhere in the '028 patent. The valve 511 is operable in responseto electric current and is capable of being modulated or throttled forselective full opening, closing and intermediate opening or “throttle”positions. Operation of the valve is generally described in U.S. Pat.No. 7,299,112 which is incorporated herein by reference. It should benoted that 122 and 124 are interchangeable such that the voice coil maybe either 122 or 124 and the magnet may be the other of 122 and 124respectively. The voice coil 122 or 124 responds to input current fromthe power circuit (e.g. position control circuit or other suitableelectrical input as described herein). As such input wiring isdesirable. The input wiring and terminals for the 122 version of thevoice coil is shown at 250. The input wiring and terminals for the 124version of the voice coil is shown at 251 and includes windings 252 toaccommodate extension and contraction of the throughput wires 252 duringoperation of the valve 200

The valve 200 is shown in a closed, or downward 256, position. As such,piston 116 fully obstructs orifices 114 thereby preventing fluid fromflowing from damper assembly 630, through channel 636, into upperchamber 253, through orifice 114, through valve outlet 257 and intofloating piston compensator chamber 254. When current of an appropriatemagnitude is applied to the voice coil 122 or 124, the magnetelectromagnet combination of 122 and 124 causes the back iron 126, andcorrespondingly the valve piston 116, to move upward 255 in an amountproportional to the voice coil input. Such upward 255 movement isagainst spring 118, which biases the valve piston 116 downward 256 (i.e.toward closed), and therefore when the voice coil input balances withthe force of spring 118, movement of the piston 116 will stop and thevalve 200 will be correspondingly throttled.

In operation, referring also to FIG. 4, the sensor (or generator) 155 or120/115 or both puts out a voltage change corresponding to an inducedrelative movement of the rod 105 and cylinder 110 of the damper 100. Inone embodiment the sensor senses input force along a prescribed axis150. As described herein. Generated power may be routed though the powerconditioner 135 which may in turn send power to the valve of FIG. 5B. Inone embodiment, the valve of 5B is biased open (not shown by extendingthe length of valve 116 downward (direction 256) and placing a hole in116 adjacent the hole 114, as the valve 116 is moved upwardly by appliedelectric current, the holes become misaligned thereby closing the valve511) and is closed gradually in response to increasing power input toterminals 250 or 251. As the shock damper 100 is worked more frequently,it generates more power and heat. The heat causes damping fluid tobecome thinner. In order to optimize performance as heat increases it isdesirable to close the damping fluid valve 511 thereby providing greaterrestriction to flow and maintaining damping rate. A similar result maybe obtained by using TEG 130 in a passive heat removal role as anelectric generator. In one embodiment, current is conducted from the TEGto the terminals 251 or 250 of the open biased (not shown but describedherein) valve 511. As the TEG heats up it causes a closure of valve 511in response thereto and thereby compensates (maintains damping rate) thedamper for increased temperature.

Referring additionally to FIG. 4, when the sensor 120/115 puts out avoltage corresponding to a bump (and/or optionally a dip) that voltageis transmitted to a processor 135. In one embodiment the shock absorberof FIGS. 4 and 5A and 5B including valve 511 is responsive to signalsand power transmitted to the valve (e.g. at 251, 250) from thecontroller 135. The valve 511 is default in the closed position and willthrottle open corresponding to power input received at terminals 250.The processor 135 compares the output voltage of sensor 155 or 120/115to a preset (by means of threshold adjuster) value and if that value isexceeded, the controller routes a predetermined amount of power from thepower source (battery and/or capacitor not shown or 120/115 or 130 orother generator directly) to the valve 511. When the output voltagefalls below the threshold value, power to the valve 511 is shut off.Optionally the valve 511 may be of a type described in U.S. Pat. No.6,073,736 which is incorporated, in its entirety, herein by reference.Optionally, the valve control/power circuit may be configured andoperable in a manner such as disclosed in U.S. Pat. Nos. 5,971,116 and6,073,736 each of which is herein incorporated, in its entirety, byreference, or by any other means or method disclosed herein or anysuitable combinations or portions thereof.

In one embodiment a mechanism that transduces temperature change intophysical movement is used to operate at least one damping valve(s),thereby compensating the damping rate for temperature changes. Referringto FIG. 5B, and in the context of the herein described applicationthereof, one embodiment includes a bimetallic (or bi-material composite)spring 118 or element placed in thermal communication with the dampingfluid. As the damping fluid heats, during use, the bimetallic elementdeforms (e.g. curls or bends) in response to the different thermalexpansion coefficients of the two dissimilar metals composing theelement. The bending or movement of the element is used to operate valvemember 116 toward a closed position. In such embodiment a second“regular” spring (not shown) is retained axially, in fixed relation tobody 273, within space 257 such that the “regular” spring exerts anaxial upward 255 force on valve 116 thereby biasing it open. The bimetalspring 118 must be heated enough by damping fluid so as to overcome thebiasing force of the “regular” spring. As such, when the damper issufficiently cooled the “regular” spring opens the valve 511.

Generally bimetal strips, springs or other elements may be used tooperate a valve as desired (e.g. close, open, choke or throttle) withinthe damping fluid chamber (e.g. on the damping piston) to modulate thedamping fluid flow area as desired in view of the temperature induceddamping fluid changes. (e.g. close or choke valves to compensate forthinner damping fluid). U.S. Pat. Nos. 5,381,952 and 4,131,657, each ofwhich is incorporated herein, in its entirety, by reference, describeconfigurations and applications for bimetal actuated valve members.

Optionally, temperature change may converted to physical movement using“shape memory” alloys such as Nitinol (a Raychem trade name for anickel-titanium shape memory alloy) or certain two phase brass alloyshaving shape memory characteristics (also available from Raychem). Valveoperating mechanisms may comprise shape memory alloys programmed tochange shape at a certain “trigger” temperature and thereby operating adamping valve or valves using motion in between their original andprogrammed shapes. Shape memory alloys may, with minimal if anyalteration in design, be used in place of bimetal elements and viceversa as temperature sensitive operational characteristics are similar.The bimetal valve spring as described herein may alternatively be aNitinol (or other shape memory alloy) spring. U.S. Pat. Nos. 6,840,257;6,073,700; and 4,570,851 each of which is incorporated herein, in itsentirety, by reference, describe configurations and applications forshape memory alloy actuated valve members. In one embodiment, the valveshown in U.S. Pat. No. 6,840,257 may be placed within the flow path 160of FIG. 4 thereby modulating damping fluid flow through piston 165 inresponse to damping fluid temperature changes. Optionally the flow path160 may be substantially closed off except for a flow path through avalve or valves placed therein.

Any valve operator mechanism disclosed herein may be used with one ormore valves of a multi-valve damping system (or other suspension systemsuch as spring) such as for example where two valves are open for “cold”temperature suspension operation and one valve is closed for “hot”suspension operation.

Optionally temperature or strain rate (i.e. induced damping rate)compensation mechanisms include shear thickening fluids (liquids). Suchliquids increase in strength as shear stress is applied. In oneembodiment such a fluid becomes more resistant to flow through anorifice (e.g. in a damping system) as the flow rate requirement orinduced damping rate is increased. In lay terms: the harder asuspension, containing a shear thickening damping fluid, is “hit”, themore rigid the suspension will behave because the damping force is ratedependent. Electro-thickening or magneto-resistive liquids can be usedto a similar end if an electric current is applied to such liquid inproportion to the induced damping rate (the induced damping rate beinginduced by, and proportional to, the severity of the impact imparted tothe suspension). In one embodiment electrical generators as disclosedherein power a magnetic coil surrounding a portion of a magneto-resitivedamper. As the suspension is operated, electrical current is generatedin proportion to the rate of operation (impact rate) and the currentflows through the magnetic coil. The energized magnetic coil causes themagneto-resistive fluid to thicken there by increasing the damping rate.Alternatively a generator as disclosed herein (or a battery/capacitor)is switched to apply current to the magnetic coil when induced operationrates are low (and/or of low amplitude) and to bypass the magnetic coilas induced operation rates increase. As such the suspension will exhibitmore damping compliance (lower damping rate) when induced operationalrates increase.

When gas becomes entrained in a damping liquid, the apparent density ofthe emulsified liquid is reduced. That can happen when an “open bath”damper is used vigorously over a period of time. The gas and liquid inthe damper become commingled at the gas/liquid interface and as usecontinues, the intermingled fluid migrates though the damping systemuntil the damping mechanism is at least partially subverted (becauseless dense fluid flows more rapidly through metering channels andvarious orifices that facilitate the dampening effect). One option fordealing with entrained gas is to include a mechanical “gas buster” inthe fluid flow path within the dampening mechanism. One complicatedexample of a “gas buster” or separator is a mechanical cyclone. Mixedgas/liquid (e.g. emulsion) enters the cyclone tangentially at a majordiameter of the cyclone so that the mixture flows in a substantiallytangential spiral within the cyclone. Due to centrifugal force, the lessdense gas migrates toward the longitudinal axis of the cyclone (aboutwhich flow spirals) and exits the cyclone on the axis at the top. Themore dense liquid phase continues in tangential flow downward in adecreasing diameter toward an outlet at the bottom of the cyclone. The“top” and “bottom” of the cyclone are relative though such terms areoften used in relation to the earth. In one embodiment, a miniaturecyclone is placed on a piston movable through a damping fluid filledcylinder. The top of the cyclone is attached to a flexible, ortelescopic, tube that has an outlet end in fluid communication with aregion of the suspension damper normally containing gas. The lower endof the cyclone is in fluid communication with a trailing side of thepiston and the cyclone inlet is in communication with a leading side ofthe piston. Such a piston would “scrub” the damping fluid of gas onevery stroke of the piston through the damping cylinder. In oneembodiment the separator comprises an abrupt 180 degree flow directionchange. The principle of the 180 degree bend or flow tube is similar tothat of the cyclone in that they both rely on the fact that the kineticenergy of the liquid is greater than the kinetic energy of the gastraveling a the same velocity. A 180 degree bend tube includes exitports at the bend and the liquid layer, being at the outside radius ofthe bend, will exit through the ports while the gas will continue thoughthe bend. The separate gas and liquid streams may be disposed of asdescribed herein.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

I claim:
 1. A vehicle suspension damper comprising: a hydraulic dampingcylinder comprising an inner wall and an outer wall, said inner wall andsaid outer wall defining an annular space therebetween; a coolingcircuit having an attachment to an said hydraulic damping cylinder,wherein said attachment is configured to facilitate heat transferbetween said cooling circuit and said hydraulic damping cylinder; and apower conditioner coupled to said cooling circuit and a set of windingterminals that are attached to said hydraulic damping cylinder and awire motor winding positioned in said annular space between said innerwall and said outer wall, wherein said power conditioner is configuredto power said cooling circuit, and wherein conditioned power isconducted, via a set of conduits, from a set of output terminals of saidpower conditioner to a set of input terminals of said cooling circuit.